// build the acceleration structure
void Bvh::Build()
{
// malloc memory
mallocMemory();
// build bounding box
computeBBox();
// generate bvh primitives
for( auto primitive : *m_primitives )
SORT_MALLOC_ID(Bvh_Primitive,BVH_LEAF_PRILIST_MEMID)(primitive);
// recursively split node
m_root = new Bvh_Node();
splitNode( m_root , 0 , m_primitives->size() , 0 );
}
void sort(){
mallocMemory();// malloc memory for each temporary file
MinHeap<MergeSortInfo<DataType> > mh(tempFileNumber);
// write the sorted file in file.
int fd = open(gfn.sortedFileName().c_str(),O_CREAT|O_RDWR,0777);
int sortedIndex = 0;// edge index in buffer
int sortedBytes = 0;// sorted bytes
int writeDataSize = sizeof(DataType);
DataType *sortedArray= (DataType *)malloc(WRITE_BUFFER_NUMBER * writeDataSize);
int sourceNumber = tempFileNumber;
//the index of each file
int *positions = (int *)malloc(sourceNumber * sizeof(int));
for(int i = 0; i < sourceNumber; i ++){
mh.insert(MergeSortInfo<DataType>(i,loadedData[i][0]));
positions[i] = 0;
}
while(sourceNumber > 0 || mh.heapSize() != 0){
MergeSortInfo<DataType> temp = mh.removeMin();
sortedArray[sortedIndex] = temp.element;
sortedBytes += writeDataSize;
if(++ sortedIndex == WRITE_BUFFER_NUMBER){
writeFile<DataType>(fd,sortedArray,sortedBytes);
sortedBytes = 0;
sortedIndex = 0;
}
int minIndex = temp.arrayIndex;
-- loadedDataNumber[minIndex];
if(loadedDataNumber[minIndex] == 0){
int leftDataNumber = eachFileDataNumber[minIndex];
if(leftDataNumber > 0){
int loadNumber = (leftDataNumber < loadedBudgetNumber)?leftDataNumber:loadedBudgetNumber;
int fd = open(gfn.binaryTempFileName(minIndex).c_str(),O_RDONLY);
int offset = eachFileSize[minIndex] - eachFileDataNumber[minIndex] * sizeof(DataType);
readFile<DataType>(fd,loadedData[minIndex],loadNumber * sizeof(DataType),offset);
close(fd);
loadedDataNumber[minIndex] = loadNumber;
eachFileDataNumber[minIndex] -= loadNumber;
positions[minIndex] = 0;
mh.insert(MergeSortInfo<DataType>(minIndex,loadedData[minIndex][positions[minIndex]]));
}
else{
-- sourceNumber;
remove(gfn.binaryTempFileName(minIndex).c_str());
}
}
else{
mh.insert(MergeSortInfo<DataType>(minIndex,loadedData[minIndex][++ positions[minIndex]]));
}
}
if(sortedBytes > 0){
writeFile<DataType>(fd,sortedArray,sortedBytes);
}
close(fd);
free(sortedArray);
mh.release();
free(positions);
std::cout << "Finish sort graph." << std::endl;
releaseMemory();
}